Diabetes remains the leading cause of non-traumatic lower extremity amputations. Most amputations are preceded by a foot ulcer, so that successfully treating, or better still preventing, foot ulcers should reduce the number of diabetes related amputations. The majority of foot ulcers in diabetic patients are the result of loss of protective sensation (LOPS) secondary to neuropathy that permits unperceived injury. Since neuropathy cannot presently be reversed, protecting the foot with LOPS from injury is the next best strategy, and footwear has long been considered to be the most important approach to primary and secondary foot ulcer prevention. Not surprisingly most neuropathic ulcers are plantar, occurring at points of high plantar loading, so that insoles that redistribute load and therefore reduce pressure should reduce plantar ulcer rates and therefore amputation risk. However, a problem in this field had been that clear algorithms to reliably and reproducibly design and manufacture insoles that off-load highly loaded sites on the plantar surface had not been developed and validated. Under the Phase I &II SBIR funding (R44 DK59074) DIApedia LLC has now completed the development of the TrueContour" insole that accomplishes this goal and, for the first time, incorporates both the shape of the foot as well as the walking plantar pressure pattern into the design rules. In a recent clinical trial, TrueContour" insoles have been shown to predictably reduce plantar pressure at forefoot sites by 21- 36% and force-time integral by 40% and 34% (both P <0.0001) compared to prior industry standard insoles based on shape only. TrueContour" insoles are also often better than iteratively produced highly customized insoles produced by expert clinicians. In this proposed randomized controlled blinded clinical trial we will now test the clinical efficacy of TrueContour" insoles in preventing foot ulcer recurrence in patients with previous and now healed plantar neuropathic foot ulcers. This will be a three-year multi-center trial with rolling enrolment and 15 months of follow up for each patient. Recurrence rates of 10-60% within the first year have been reported in the literature for patients with a prior plantar ulcer. 286 patients with LOPS and a plantar ulcer healed within the last three months will be randomized to receive TrueContour" insoles or current standard of care insoles. In-shoe plantar pressure will be measured after a two-week `break in'to document the enhanced off-loading efficacy of the TrueContour" insoles. Shoe use during the 15 month period will be monitored by a novel shoe-mounted step sensor. Patients will be blinded to condition all insoles will be supplied from central fabrication facilities without identification. End-points will be assessed from photographs by an Ulcer Adjudication Panel blinded to the treatment assignment. This study will clarify whether or not footwear that reliably reduces plantar pressure at sites of prior ulceration also reduces the risk for ulcer recurrence. In addition, a positive result will further our effort to bring this product to a wider market. It will also provide the information needed to petition CMS for new codes for this new generation of quantitatively designed therapeutic insoles. PUBLIC HEALTH RELEVANCE. Diabetes is responsible for most of the amputations in the US that are not caused by accidents. Most such amputations start with a foot ulcer that the person cannot feel, because of nerve damage that can develop due to diabetes in some people. Well fitting shoes with insoles that cushion the bottom of feet should protect diabetic patients with nerve damage, and prevent ulcers and amputations. While many shoes and insoles are sold for this purpose, there have not until now been precise rules for how such insoles should be made. DIApedia LLC has for the first time developed such rules, based on the patient's foot shape and for the first time also on the pressure pattern under an individual's foot. We are now proposing to test whether these highly customized insoles can prevent foot ulcers in patients who have had at least one prior ulcer that has been treated and healed. If successful, this line of research should reduce the number of amputations due to diabetes.